by Annie Vreeland (Vanderbilt University)
75,000 characters, 90 different cipher letters, 105 pages, and 300 years later, Kevin Knight and his colleagues finally cracked the mysterious Copiale Cipher. The Copiale Cipher is a manuscript from the 18th century belonging to a German secret society known as the “Oculist Order.” The only plaintext that appears among the mix of Roman and Greek letters and abstract symbols is “Philipp 1866,” the alleged owner of the manuscript, and “Copiales 3,” which is where the secret document got its name. The document was discovered in a library in East Germany in 1970, but was neglected until 2011 when teams in the US and Sweden cracked, studied, and released the Cipher. Kevin Knight, a computer scientist at the Information Sciences Institute at the University of Southern Califonia, started deciphering the Copiale Cipher as a weekend project. Knight’s curiosity overtook him and he began to collaborate with Beata Megyesi and Christiane Schaefer of Uppsala University in Sweden, who helped him decipher the first 16 pages of the document.
Imagine receiving a 105-page note that was comprised of a combination of letters and abstract symbols, with no word spacing, no chapter breaks, and no illustrations – where would you even start the decoding process? Kevin Knight, Dr. Beata Megyesi, and Christiane Schaefer asked themselves the same question. Not knowing the language or topic of the document, they went with their gut feeling and assumed that the letters sprinkled throughout the text were Roman and Greek characters. The code breaking team tried 80 different languages, when they finally decided to give up on their hypothesis. It turns out the letters were nulls, meaning they were thrown into the mix to confuse and mislead readers, “somewhat like how pig Latin adds the suffix ‘ay’ to words in an attempt to confuse listeners” (LiveScience 2011). The only meaningful characters left for Knight and his team to decode were the abstract symbols that had never been seen before.
The team then came up with a theory that similar shapes represented the same letter or groups of letters, “for instance, the symbols with the circumflex ^ over them were actually the letter “E” (LiveScience 2011). This means that the Copiale Cipher is an advanced substitution cipher; basically letters like “th” are replaced with symbols such as _*. At this point, it would be helpful to know what language to translate these symbols into. Knight and his team hypothesized that the plaintext language was most likely German, as the book was located in Germany and the spelling of ‘Philipp’ in the inscription was German. So thus far, Knight assumed that it is a substitution cipher, where letters are replaced by symbols, and the plain text language is German. The next step he took was to look at the frequency analysis. This is where the computer calculates how often different symbols occur and where they occurred together. They found one three-symbol combination in the cipher text that translated into “cht,” a standard German trio, which confirms their hypothesis. The frequency analysis allowed them to evaluate what letters are most common in German and compare it to what letters appear most often in the cipher, which is how Knight could tease out enough letters to identify the words “Ceremonies of Initiation” followed by “Secret Section.” At this point, after many possibilities are eliminated and the team was set on a hypothesis and started to use the computer as an aid to fully translate the document.
The 75,000-character document was written on double-watermarked paper and was bound by gold and green brocade paper. The manuscript was found after the Cold War in the “archive of the East Berlin Academy, which later merged with West Berlin Academy to become the Academy of Arts, Berlin” (Baker 2012). Analysts of the paper believe it dates back to around 1760-1780. Although the origin of the Copiale cipher is unknown, Knight and his team were able to make sense of the entire plaintext. They found that the manuscript was divided into three parts. The first part of the document described the Oculist society rituals, the second part discusses other 18th century Masonic rituals, and the third part discussed other forms of modern Freemasonry. The Society’s rituals include “the initiation of a candidate and the first few degrees of progression” (Baker 2012). During this time, the book of Oculist society law was presented, the apprentice learned secret lessons, and there were ceremonies of initiation. If someone wanted to be initiated into this society, they must first pledge secrecy and fidelity to the Oculist society. They are then presented with a blank piece of paper and asked to read it aloud, but confess that they do not have the ability to read it. They are then given eyeglasses and asked to try reading aloud again and the answer is still no. But wait, the ritual gets weirder: the Master then plucks a hair from the candidate’s eyebrow and washes his eyes. When the candidate looks back down at the blank sheet, there is a book of teaching for apprentices instead. With the instructions from this book on how to behave as an apprentice, the pledge is finally initiated into the society. The second part of the Copiale document describes typical 18th century Masonic rituals. The final part “provides an insight into other forms of contemporary Freemasonry,” (Baker 2012) for example the Scottish rites that were popular in Germany at that time.
The Copiale Cipher is a newly discovered and deciphered code that allows us to look into the customs of a German secret society. From the brief description of the ritual, it appears that the Oculist Order was obsessed with ophthalmology, the study and treatment of the eye. Interestingly enough, Knight claims that the symbol of many secret societies is the eye, which helps to explain the society’s fixation. This insight also implies that the members of the Oculist Order were not necessarily ophthalmologists themselves. On another note, this cipher is special because many Masonic ciphers still remain unbroken today. The fact that Knight has cracked this cipher provides other code breakers with techniques and algorithms that can be used in machine translation and are useful when deciphering other unknown texts. Following Knight’s efficient deciphering technique, you now have all of the tips for deciphering that mysterious 105-page note that lands on your doorstep.
This post is part of a series of essays on the history of cryptography produced by students at Vanderbilt University. The students wrote these essays for an assignment in a first-year writing seminar taught by mathematics instructor Derek Bruff. The essays are shared here, in part, to give the students an authentic and specific audience for their writing. For more information on this cryptography seminar, see the course blog.
Baker, D. (2012, June 22). The Oculist’s Secret Society. The Optician, 243(6357), 22-23. doi:1026948309
LiveScience, C. C. (2011, October 26). Copiale Cipher: How a Secret Society’s Code was Finally Cracked. The Christian Science Monitor, Science. doi:900584643
Image: “eye,” Helga Birna Jónasdóttir, Flickr (CC)